Loose Skin Post Weight Loss, What Are My Options? (photo)

I used to be significantly overweight (I do not know the exact weight but I'm guessing 95kg at a height of around 5"5). Due to a complete change in lifestyle and identification of certain allergies, I lost around 40kg rapidly in the space of 8 months, and now weigh between 52-55kg. I was 13 then, and now am 17. The issue is that I've been left with a bit of loose skin (and many stretch marks) that really affect my self esteem to the point where it has made me depressed. What are my options?